In the last years, some progress has been made in the development of equipment for the packaging of fresh food products.
EP 1226408 discloses weighing and portioning techniques bases on grader technique, where a number of items which are to be portioned out, namely natural foodstuff items with varying weight, are subjected to a weighing-in and are thereafter selectively fed together in a computer controlled manner. According to this reference, a transport equipment of a robotic type having an associated control unit is used for arranging the allocation of the individual items to respective receiving stations for items for the different groups, and for the related selective control of the transport equipment. In one embodiment a carton packing is placed for thereby enabling a direct packaging.
Similar disclosure but for poultry packaging may be found in “Robotic Packaging of Poultry products, by K. Khodabandehloo, Department of Mechanical Engineering, University of Bristol ISBN 0442316615 (Routledge, 1992)” and “Benefits of Experts robots intelligence vs. Skill, by K. Khodabandehloo, Department of Mechanical Engineering, University of Bristol ISBN 0387537317 (Routledge, 1992)”. There, a robotisation is disclosed for placing poultry portions in trays according to a defined scheme with a requirement of minimum overweight in the trays.
The disadvantage with the above references is that in order to obtain portions with a minimum overweight it is necessary to have a large amount of containers, e.g. trays, boxes etc. As an example, in an extreme situation that there are two containers that are to be filled simultaneously, the robotic system does have a very limited choice when generating these portions. Another disadvantage in these references is that a large number of containers requires a large space area. This can result in that the robotic systems but be adapted to the large space, e.g. with long transport arms, but as the robot arms are longer the fewer articles per minute they can displace. Another option is to use more robot arms but that will result in significantly higher costs. Furthermore, this means that in an extreme situation that 50 containers are to be filled, one would obviously need a number of robots to perform the operation described in these references.
Another disadvantage of having robot arm picking the articles up from a conveyor is that it is difficult to design a good gripper arm to handle, e.g. grasping, delicate food products which typically come in various sizes. If the gripper arm is big enough for the biggest articles it will require significantly more space between small articles than would otherwise be needed.